package com.heima.kafka.sample;

import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.TopicPartition;

import java.time.Duration;
import java.util.Collections;
import java.util.Map;
import java.util.Properties;

/**
 * 消费者
 */
public class ConsumerQuickStart {
    public static void main(String[] args) {
        //1.添加kafka的配置信息
        Properties properties = new Properties();
        //kafka的连接地址
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.200.130:9092");
        //消费者组  随意起名
        properties.put(ConsumerConfig.GROUP_ID_CONFIG, "group1");
        //消息的反序列化器
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");


        //手动提交偏移量
        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG,false);



        //2.消费者对象
        KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(properties);

        //3.订阅主题 TODO Collections.singletonList被限定只被分配一个内存空间，也就是只能存放一个元素的内容。
        consumer.subscribe(Collections.singletonList("itheima-topic"));

        //当前线程一直处于监听状态，不让死掉
/*        while (true) {
            //4.获取消息
            ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));//设置拉取频率
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord.key());
                System.out.println(consumerRecord.value());
                System.out.println(consumerRecord.partition());
                System.out.println(consumerRecord.offset());//消费到了什么位置

                //同步提交偏移量
         *//*       try {
                    consumer.commitSync();//同步提交当前最新的偏移量
                }catch (CommitFailedException e){
                    System.out.println("记录提交失败的异常："+e);
                }
*//*
            }

            //异步方式提交偏移量  在for循环外写
*//*
            consumer.commitAsync(new OffsetCommitCallback() {
                @Override
                public void onComplete(Map<TopicPartition, OffsetAndMetadata> map, Exception e) {
                    if(e!=null){
                        System.out.println("记录错误的提交偏移量："+ map+",异常信息"+e);
                    }
                }
            });
*//*
        }*/



        //同步和异步提交偏移量
        try{
            while (true) {
                //4.获取消息
                ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));//设置拉取频率
                for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                    System.out.println(consumerRecord.key());
                    System.out.println(consumerRecord.value());
                    System.out.println(consumerRecord.partition());
                    System.out.println(consumerRecord.offset());//消费到了什么位置

                    consumer.commitAsync();//异步提交
                }
            }
        }catch (Exception e){
            e.printStackTrace();
            System.out.println("记录错误信息："+e);
        }finally {
            try {
                consumer.commitSync();//同步提交
            }finally {
                consumer.close();
            }
        }





    }
}
